TTL connection

[przemo]

G'Day
Iam an begginer so forgive me if tha qoestiom seems trivial.
I use an PCL-818HG card and a Dasylab 5.6 to monitor an analog signals and a TTL signal. Now I have the TTL signal connected to an analog channel, but due to it has up to 40khz frequency it is very inconvenient. I would like to utilize its digital nature. when I tried to connect it to an digital channel, but I can't get any reading from that - all the channels shows +5V when I read them by an meter.
I connected 0V to digital gnd terminal and +5V to timer or pacer or clk terminal - always the same.
furthermore I want to use that TTL to read those analog signals exactly when rising edge appears and cut out all other values. when using an rely module in dasylab with action driving it does not wont to block transmission after one sample pass.
please, guide me how to connect the signal and how to prepare correct triggering instalation.
regards,
przemyslaw

[Salvador_Santolucito]

Hi Przemo,

I think that your board may only support single point digital IO operations (not timed buffered). This means that in software you have to read the digital ports repeatedly using a loop. You cannot simply say that you want to read 1000 points from the digital line and read 1000 words. This type of buffered digital acquisition would require a board that uses handshaking. This will be very hard to support since DaisyLab is so old and you are not using an NI board. If this application is very important I would HIGHLY suggest moving to one of our DAQ boards and LabVIEW. In the end you will save a lot of time and expense by gong with NI hardware/software since it is tightly integrated. Also you will have much better support with NI products.

Thanks,
Sal